From the FAQ:
Do you have to submit an un-edited ID to Persona?
Yes, you must send your unedited, full ID to Persona. Obfuscating, blocking, blurring, or otherwise removing information from your ID will cause a failure to verify.
Is Persona subject to the GDPR?
Yes, it is. Any company or organization that processes data of users within the EU must comply with the GDPR, even if they aren’t based in the EU (GDPR Article 3).
Those 2 don't go together,
Art. 5 (1) (b) of the GDPR
> collected for specified, explicit and legitimate purposes and not further processed in a manner that is incompatible with those purposes;
Art. 5 (1) (c) of the GDPR
> adequate, relevant and limited to what is necessary in relation to the purposes for which they are processed (‘data minimisation’);
Art. 25 (2) of the GDPR
> The controller shall implement appropriate technical and organisational measures for ensuring that, by default, only personal data which are necessary for each specific purpose of the processing are processed
meaning we are allowed to block out all information that is not needed (meaning pretty much everything except birth year (if the year alone makes it clear that we are 18+) and maybe the picture to verify that we are actually the owner of the ID)